/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package android.support.percent;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.FrameLayout;

/**
 * Subclass of {@link FrameLayout} that supports percentage based dimensions and
 * margins.
 *
 * You can specify dimension or a margin of child by using attributes with
 * "Percent" suffix. Follow this example:
 *
 * <pre class="prettyprint">
 * &lt;android.support.percent.PercentFrameLayout
 *         xmlns:android="http://schemas.android.com/apk/res/android"
 *         xmlns:app="http://schemas.android.com/apk/res-auto"
 *         android:layout_width="match_parent"
 *         android:layout_height="match_parent"/&gt
 *     &lt;ImageView
 *         app:layout_widthPercent="50%"
 *         app:layout_heightPercent="50%"
 *         app:layout_marginTopPercent="25%"
 *         app:layout_marginLeftPercent="25%"/&gt
 * &lt;/android.support.percent.PercentFrameLayout/&gt
 * </pre>
 *
 * The attributes that you can use are:
 * <ul>
 * <li>{@code layout_widthPercent}
 * <li>{@code layout_heightPercent}
 * <li>{@code layout_marginPercent}
 * <li>{@code layout_marginLeftPercent}
 * <li>{@code layout_marginTopPercent}
 * <li>{@code layout_marginRightPercent}
 * <li>{@code layout_marginBottomPercent}
 * <li>{@code layout_marginStartPercent}
 * <li>{@code layout_marginEndPercent}
 * </ul>
 *
 * It is not necessary to specify {@code layout_width/height} if you specify
 * {@code layout_widthPercent.} However, if you want the view to be able to take
 * up more space than what percentage value permits, you can add
 * {@code layout_width/height="wrap_content"}. In that case if the percentage
 * size is too small for the View's content, it will be resized using
 * {@code wrap_content} rule.
 */
public class PercentFrameLayout extends FrameLayout {
	private final PercentLayoutHelper mHelper = new PercentLayoutHelper(this);

	public PercentFrameLayout(Context context) {
		super(context);
	}

	public PercentFrameLayout(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	public PercentFrameLayout(Context context, AttributeSet attrs,
			int defStyleAttr) {
		super(context, attrs, defStyleAttr);
	}

	@Override
	public LayoutParams generateLayoutParams(AttributeSet attrs) {
		return new LayoutParams(getContext(), attrs);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
		if (mHelper.handleMeasuredStateTooSmall()) {
			super.onMeasure(widthMeasureSpec, heightMeasureSpec);
		}
	}

	@Override
	protected void onLayout(boolean changed, int left, int top, int right,
			int bottom) {
		super.onLayout(changed, left, top, right, bottom);
		mHelper.restoreOriginalParams();
	}

	public static class LayoutParams extends FrameLayout.LayoutParams implements
			PercentLayoutHelper.PercentLayoutParams {
		private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;

		public LayoutParams(Context c, AttributeSet attrs) {
			super(c, attrs);
			mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c,
					attrs);
		}

		public LayoutParams(int width, int height) {
			super(width, height);
		}

		public LayoutParams(int width, int height, int gravity) {
			super(width, height, gravity);
		}

		public LayoutParams(ViewGroup.LayoutParams source) {
			super(source);
		}

		public LayoutParams(MarginLayoutParams source) {
			super(source);
		}

		public LayoutParams(FrameLayout.LayoutParams source) {
			super((MarginLayoutParams) source);
			gravity = source.gravity;
		}

		@SuppressLint("NewApi")
		public LayoutParams(LayoutParams source) {
			this((FrameLayout.LayoutParams) source);
			mPercentLayoutInfo = source.mPercentLayoutInfo;
		}

		@Override
		public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo() {
			return mPercentLayoutInfo;
		}

		@Override
		protected void setBaseAttributes(TypedArray a, int widthAttr,
				int heightAttr) {
			PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr,
					heightAttr);
		}
	}
}
